1. Field of the Invention
This invention relates to dispensers for fluid materials. It is particularly but not necessarily concerned with dispensers from which the material is ejected as a spray.
2. The Related Art
Aerosols which are used to spray a fluid material from a dispenser suffer from a number of disadvantages, including the adverse environmental effect of the propellant gases used, the high proportion of the total capacity of the dispenser that is sometimes needed for the propellant, and the difficulty of maintaining the spray pressure as the contents of the dispenser are used up. The disposal of the partly empty dispensers can also be a hazard because of the pressurized gases they contain. The present invention is concerned with a novel form of dispenser in which at least some of these disadvantages can be avoided.